Three-piece compact optical lens system

ABSTRACT

A three-piece compact optical lens system includes, in order from the object side to the image side: a flat panel assembly made of glass, a first lens element with a negative refractive power having an object-side surface being concave near an optical axis; a stop; a second lens element with a positive refractive power having an object-side surface being convex near the optical axis and an image-side surface being convex near the optical axis; and a third lens element with a positive refractive power. Such a system can not only effectively collect light at a large angle, receive a wider range of images and achieve identification effects within very short distances, but also can reduce the distance between an object and the three-piece compact optical lens system, reduce the volume effectively and maintain its miniaturization.

BACKGROUND Field of the Invention

The present invention relates to a lens system, and more particularly to a three-piece compact optical lens system applicable to electronic products.

Description of the Prior Art

The biometric identification (biometric) system based on the unique biometric characteristics of each organism, because of its uniqueness, universality, permanence, testability, convenience, acceptability, and impermissibility, it is often used in existing mobile devices on the current market, or even in future electronic devices. However, at present, the biometric identification system used in mobile devices is based on the principle of capacitance. Although it can reduce the required volume of the biometric identification system, the circuit structure is too complex, which makes the manufacturing cost too high, and the relative unit price of the product is also higher.

Although there are traditional biometric identification systems using optical imaging principles, such as fingerprint identification, vein identification and so on, the traditional biometric identification systems have the problem of too large volume, which makes it difficult to miniaturize the electronic devices equipped with the biometric identification systems, and it is also harder to carry.

The present invention mitigates and/or obviates the aforementioned disadvantages.

SUMMARY

The primary objective of the present invention is to provide a three-piece compact optical lens system which can reduce the distance between an object and the three-piece compact optical lens system, reduce the volume effectively, and maintain its miniaturization.

Another objective of the present invention is to provide a three-piece compact optical lens system which can effectively collect light at a large angle, receive a wider range of images and achieve identification effects within very short distances.

Therefore, a three-piece compact optical lens system in accordance with the present invention comprises, in order from an object side to an image side: a flat panel made of glass; a first lens element with a negative refractive power having an object-side surface being concave near an optical axis, at least one of the object-side surface and an image-side surface of the first lens element being aspheric; a stop; a second lens element with a positive refractive power having an object-side surface being convex near the optical axis and an image-side surface being convex near the optical axis, at least one of the object-side surface and the image-side surface of the second lens element being aspheric; and a third lens element with a positive refractive power, at least one of an object-side surface and an image-side surface of the third lens element being aspheric.

Wherein the three-piece compact optical lens system has a total of three lens elements with refractive power, the three-piece compact optical lens system has a maximum view angle FOV, a distance from an object on an object-side surface of the flat panel to an image plane along the optical axis is OTL, a focal length of the three-piece compact optical lens system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, and they satisfy the relations: 90 degrees<FOV<140 degrees; 2 mm<OTL<6 mm; 0.2 mm⁻²<|f/(f1*f2*f3)|<0.7 mm⁻².

Preferably, the focal length of the three-piece compact optical lens system is f, the focal length of the first lens element is f1, and they satisfy the relation: −0.7<f/f1<−0.1, so that the refractive power of the three-piece compact optical lens system can be balanced, so as to correct the aberration of the three-piece compact optical lens system effectively and reduce the sensitivity of the three-piece compact optical lens system.

Preferably, the focal length of the three-piece compact optical lens system is f, the focal length of the second lens element is f2, and they satisfy the relation: 0.1<f/f2<0.75, so that the refractive power of the three-piece compact optical lens system can be balanced, so as to correct the aberration of the three-piece compact optical lens system effectively and reduce the sensitivity of the three-piece compact optical lens system.

Preferably, the focal length of the three-piece compact optical lens system is f, the focal length of the third lens element is 13, and they satisfy the relation: 0.07<f/f3<0.68, so that the refractive power of the three-piece compact optical lens system can be balanced, so as to correct the aberration of the three-piece compact optical lens system effectively and reduce the sensitivity of the three-piece compact optical lens system.

Preferably, the focal length of the three-piece compact optical lens system is f, a focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: 0.4<f/f23<1.0, so that the shortening of the total length of the system and the correction of aberration can be balanced.

Preferably, the focal length of the first lens element is f1, the focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: −2.9<f1/f23<−1.0, so that the resolution can be improved evidently.

Preferably, the focal length of the first lens element is f1, a radius of curvature of the object-side surface of the first lens element is R1, and they satisfy the relation: 0.6<f1/R1<2.4, which can reduce the distortion.

Preferably, the focal length of the first lens element is f1, a radius of curvature of the image-side surface of the first lens element is R2, and they satisfy the relation: −1.0<f1/R2<0.6, so that the curvature of the image-side surface of the first lens element will be appropriate, it will be favorable to reduce the total length of the three-piece compact optical lens system.

Preferably, the focal length of the second lens element is f2, a radius of curvature of the object-side surface of the second lens element is R3, and they satisfy the relation: 0.2<f2/R3<1.6, it will be favorable to reduce the sensitivity of the system, effectively improving the yield of production.

Preferably, the focal length of the second lens element is f2, a radius of curvature of the image-side surface of the second lens element is R4, and they satisfy the relation: −1.8<f2/R4<−0.4, so that it can further reduce the peripheral curvature of the image-side surface of the second lens element, and realize the characteristic of reducing stray light.

Preferably, the focal length of the third lens element is f3, a radius of curvature of the object-side surface of the third lens element is R5, and they satisfy the relation: −0.7<f3/R5<2.7, so that the magnification of imaging is corrected.

Preferably, the focal length of the third lens element is f3, a radius of curvature of the image-side surface of the third lens element is R6, and they satisfy the relation: −2.1<f3/R6<1.0, so that the magnification of imaging is corrected.

Preferably, the radius of curvature of the object-side surface of the first lens element is R1, the radius of curvature of the image-side surface of the first lens element is R2, and they satisfy the relation: −0.9<R1/R2<0.6, so that the spherical aberration and astigmatism of the three-piece compact optical lens system can be reduced.

Preferably, the radius of curvature of the object-side surface of the second lens element is R3, the radius of curvature of the image-side surface of the second lens element is R4, and they satisfy the relation: −3.2<R3/R4<−0.1, so that the astigmatism of the three-piece compact optical lens system can be reduced.

Preferably, the radius of curvature of the object-side surface of the third lens element is R5, the radius of curvature of the image-side surface of the third lens element is R6, and they satisfy the relation: −95<R5/R6<10, so that the curvature configuration of the surfaces of the third lens element can be balanced effectively, so as to balance the field of view with the total track length.

Preferably, the focal length of the three-piece compact optical lens system is f, the distance from the object on the object-side surface of the flat panel to the image plane along the optical axis is OTL, and they satisfy the relation: 8.0<OTL/f<18.0, it will be favorable to maintain the objective of miniaturization and long focus of the three-piece compact optical lens system, which can be used in thin electronic products.

Preferably, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, and they satisfy the relation: −2.4 mm⁻²<(f1+f2+f3)/(f1*f2*f3)<−0.1 mm⁻², so that the object can be well imaged on the image plane with small aberration and high relative illumination on the short object distance.

The present invention will be presented in further details from the following descriptions with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a three-piece compact optical lens system in accordance with a first embodiment of the present invention;

FIG. 1B is a partial enlarged view of FIG. 1A;

FIG. 1C shows the image plane curve and the distortion curve of the first embodiment of the present invention;

FIG. 2A shows a three-piece compact optical lens system in accordance with a second embodiment of the present invention;

FIG. 2B is a partial enlarged view of FIG. 2A;

FIG. 2C shows the image plane curve and the distortion curve of the second embodiment of the present invention;

FIG. 3A shows a three-piece compact optical lens system in accordance with a third embodiment of the present invention;

FIG. 3B is a partial enlarged view of FIG. 3A;

FIG. 3C shows the image plane curve and the distortion curve of the third embodiment of the present invention;

FIG. 4A shows a three-piece compact optical lens system in accordance with a fourth embodiment of the present invention;

FIG. 4B is a partial enlarged view of FIG. 4A;

FIG. 4C shows the image plane curve and the distortion curve of the fourth embodiment of the present invention;

FIG. 5A shows a three-piece compact optical lens system in accordance with a fifth embodiment of the present invention;

FIG. 5B is a partial enlarged view of FIG. 5A;

FIG. 5C shows the image plane curve and the distortion curve of the fifth embodiment of the present invention;

FIG. 6A shows a three-piece compact optical lens system in accordance with a sixth embodiment of the present invention;

FIG. 6B is a partial enlarged view of FIG. 6A;

FIG. 6C shows the image plane curve and the distortion curve of the sixth embodiment of the present invention;

FIG. 7A shows a three-piece compact optical lens system in accordance with a seventh embodiment of the present invention;

FIG. 7B is a partial enlarged view of FIG. 7A;

FIG. 7C shows the image plane curve and the distortion curve of the seventh embodiment of the present invention;

FIG. 8A shows a three-piece compact optical lens system in accordance with an eighth embodiment of the present invention;

FIG. 8B is a partial enlarged view of FIG. 8A; and

FIG. 8C shows the image plane curve and the distortion curve of the eighth embodiment of the present invention.

DETAILED DESCRIPTION

Referring to FIGS. 1A, 1B and FIG. 1C, FIG. 1A shows a three-piece compact optical lens system in accordance with a first embodiment of the present invention, FIG. 1B is a partial enlarged view of FIG. 1A, and FIG. 1C shows, in order from left to right, the image plane curve and the distortion curve of the first embodiment of the present invention. A three-piece compact optical lens system in accordance with the first embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 160, a first lens element 110, a stop 100, a second lens element 120, a third lens element 130, an IR cut filter 170, and an image plane 180, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 100 is disposed between the first lens element 110 and the second lens element 120.

The flat panel 160 made of glass is located between an object O and the first lens element 110 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 110 with a negative refractive power has an object-side surface 111 being concave near an optical axis 190 and an image-side surface 112 being convex near the optical axis 190, the object-side surface 111 and the image-side surface 112 are aspheric, and the first lens element 110 is made of plastic material.

The second lens element 120 with a positive refractive power has an object-side surface 121 being convex near the optical axis 190 and an image-side surface 122 being convex near the optical axis 190, the object-side surface 121 and the image-side surface 122 are aspheric, and the second lens element 120 is made of plastic material.

The third lens element 130 with a positive refractive power has an object-side surface 131 being convex near the optical axis 190 and an image-side surface 132 being convex near the optical axis 190, the object-side surface 131 and the image-side surface 132 are aspheric, and the third lens element 130 is made of plastic material.

The IR cut filter 170 made of glass is located between the third lens element 130 and the image plane 180 and has no influence on the focal length of the three-piece compact optical lens system.

The equation for the aspheric surface profiles of the respective lens elements of the first embodiment is expressed as follows:

$z = {\frac{{ch}^{2}}{1 + \left\lbrack {1 - {\left( {k + 1} \right)c^{2}h^{2}}} \right\rbrack^{0.5}} + {Ah}^{4} + {Bh}^{6} + {Ch}^{8} + {Dh}^{10} + {Eh}^{12} + {Fh}^{14} + {{Gh}^{16}\mspace{14mu}\ldots}}$

wherein:

z represents the value of a reference position with respect to a vertex of the surface of a lens and a position with a height h along the optical axis 190;

c represents a paraxial curvature equal to 1/R (R: a paraxial radius of curvature);

h represents a vertical distance from the point on the curve of the aspheric surface to the optical axis 190;

k represents the conic constant;

A, B, C, D, E, F, G, . . . : represent the high-order aspheric coefficients.

In the first embodiment of the three-piece compact optical lens system, a focal length of the three-piece compact optical lens system is f, a f-number of the three-piece compact optical lens system is Fno, the three-piece compact optical lens system has a maximum view angle (field of view) FOV, and they satisfy the relations: f=0.37 mm; Fno=1.35; and FOV=105.0 degrees.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the three-piece compact optical lens system is f, a focal length of the first lens element 110 is f1, a focal length of the second lens element 120 is f2, a focal length of the third lens element 130 is f3, and they satisfy the relation: |f/(f1*f2*f3)|=0.38 mm⁻².

In the first embodiment of the present three-piece compact optical lens system, the focal length of the three-piece compact optical lens system is f, the focal length of the first lens element 110 is f1, and they satisfy the relation: f/f1=−0.32.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the three-piece compact optical lens system is f, the focal length of the second lens element 120 is 12, and they satisfy the relation: f/f2=0.53.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the three-piece compact optical lens system is f, the focal length of the third lens element 130 is f3, and they satisfy the relation: f/f3=0.32.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the three-piece compact optical lens system is f, a focal length of the second lens element 120 and the third lens element 130 combined is f23, and they satisfy the relation: f/f23=0.75.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the first lens element 110 is f1, the focal length of the second lens element 120 and the third lens element 130 combined is f23, and they satisfy the relation: f1/f23=−2.38.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the first lens element 110 is f1, a radius of curvature of the object-side surface 111 of the first lens element 110 is R1, and they satisfy the relation: f1/R1=1.86.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the first lens element 110 is f1, a radius of curvature of the image-side surface 112 of the first lens element 110 is R2, and they satisfy the relation: f1/R2=0.02.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the second lens element 120 is f2, a radius of curvature of the object-side surface 121 of the second lens element 120 is R3, and they satisfy the relation: f2/R3=0.83.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the second lens element 120 is f2, a radius of curvature of the image-side surface 122 of the second lens element 120 is R4, and they satisfy the relation: f2/R4=−1.19.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the third lens element 130 is f3, a radius of curvature of the object-side surface 131 of the third lens element 130 is R5, and they satisfy the relation: f3/R5=0.86.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the third lens element 130 is f3, a radius of curvature of the image-side surface 132 of the second lens element 130 is R6, and they satisfy the relation: f3/R6=−0.75.

In the first embodiment of the present three-piece compact optical lens system, the radius of curvature of the object-side surface 111 of the first lens element 110 is R1, the radius of curvature of the image-side surface 112 of the first lens element 110 is R2, and they satisfy the relation: R1/R2=0.01.

In the first embodiment of the present three-piece compact optical lens system, the radius of curvature of the object-side surface 121 of the second lens element 120 is R3, the radius of curvature of the image-side surface 122 of the second lens element 120 is R4, and they satisfy the relation: R3/R4=−1.42.

In the first embodiment of the present three-piece compact optical lens system, the radius of curvature of the object-side surface 131 of the third lens element 130 is R5, the radius of curvature of the image-side surface 132 of the third lens element 130 is R6, and they satisfy the relation: R5/R6=−0.86.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the compact optical lens system is f, a distance from the object O on an object-side surface of the flat panel to the image plane 180 along the optical axis 190 is OTL, and they satisfy the relation: OTL/f=13.30.

In the first embodiment of the present three-piece compact optical lens system, the focal length of the first lens element 110 is f1, the focal length of the second lens element 120 is f2, the focal length of the third lens element 130 is f3, and they satisfy the relation: (f1+f2+f3)/(f1*f2*f3)=−0.70 mm⁻².

The detailed optical data of the first embodiment is shown in table 1, and the aspheric surface data is shown in table 2.

TABLE 1 Embodiment 1 f(focal length) = 0.37 mm, Fno = 1.35, FOV = 105 deg. sur- Curvature Thick- Ma- In- Abbe Focal face Radius ness terial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.476 3 Lens 1  −0.638 (ASP) 0.392 plastic 1.54 56 −1.19 4 −59.893 (ASP) 0.379 5 stop infinity 0.005 6 Lens 2  0.848 (ASP) 0.377 plastic 1.54 56  0.71 7 −0.596 (ASP) 0.034 8 Lens 3  1.354 (ASP) 0.244 plastic 1.64 22.5  1.17 9 −1.566 (ASP) 0.361 10 IR- infinity 0.210 glass 1.52 54.5 filter 11 infinity infinity 12 Image infinity 0.000 plane

TABLE 2 Aspheric Coefficients surface 3 4 6 7 8 9 K: −6.6639E+00 −4.0007E+02 −4.6984E+01 8.6056E−01 −2.6278E+01 −8.7212E+01 A: 2.1335E+00 6.6209E+00 4.6884E+00 −4.1935E−02 1.0201E+00 2.1905E+00 B: −6.7124E+00 11.143E+00 −6.7574E+01 −3.9365E+01 −4.6967E+01 −2.9033E+01 C: 1.5008E+01 2.8583E+02 −4.1183E+02 2.2458E+02 1.3049E+02 1.3825E+01 D: −1.8686E+01 −2.6398E+03 1.0258E+04 6.2920E+02 9.5193E+02 4.1848E+02 E: 8.7309E+00 −1.3663E+04 8.5885E+04 3.3069E+02 −4.2474E+02 4.3534E+03 F  4.9937E+00 2.4599E+05 −1.9343E+06 −6.1268E+04 −7.4096E+04 −4.8409E+04 G  −5.1320E+00 5.4409E+03 6.9233E+06 2.1063E+05 2.9197E+05 1.1285E+05

The units of the radius of curvature, the thickness and the focal length in table 1 are expressed in mm, the surface numbers 0-12 represent the surfaces sequentially arranged from the object-side to the image-side along the optical axis. In table 2, k represents the conic coefficient of the equation of the aspheric surface profiles, and A, B, C, D, E, F, G . . . : represent the high-order aspheric coefficients. The tables presented below for each embodiment are the corresponding schematic parameter, image plane curves and distortion curves, and the definitions of the tables are the same as Table 1 and Table 2 of the first embodiment. Therefore, an explanation in this regard will not be provided again.

Referring to FIGS. 2A, 2B and FIG. 2C, FIG. 2A shows a three-piece compact optical lens system in accordance with a second embodiment of the present invention, FIG. 2B is a partial enlarged view of FIG. 2A, and FIG. 2C shows, in order from left to right, the image plane curve and the distortion curve of the second embodiment of the present invention. A three-piece compact optical lens system in accordance with the second embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 260, a first lens element 210, a stop 200, a second lens element 220, a third lens element 230, an IR cut filter 270, and an image plane 280, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 200 is disposed between the first lens element 210 and the second lens element 220.

The flat panel 260 made of glass is located between an object O and the first lens element 210 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 210 with a negative refractive power has an object-side surface 211 being concave near an optical axis 290 and an image-side surface 212 being convex near the optical axis 290, the object-side surface 211 and the image-side surface 212 are aspheric, and the first lens element 210 is made of plastic material.

The second lens element 220 with a positive refractive power has an object-side surface 221 being convex near the optical axis 290 and an image-side surface 222 being convex near the optical axis 290, the object-side surface 221 and the image-side surface 222 are aspheric, and the second lens element 220 is made of plastic material.

The third lens element 230 with a positive refractive power has an object-side surface 231 being convex near the optical axis 290 and an image-side surface 232 being convex near the optical axis 290, the object-side surface 231 and the image-side surface 232 are aspheric, and the third lens element 230 is made of plastic material.

The IR cut filter 270 made of glass is located between the third lens element 230 and the image plane 280 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the second embodiment is shown in table 3, and the aspheric surface data is shown in table 4.

TABLE 3 Embodiment 2 f(focal length) = 0.38 mm, Fno = 1.40, FOV = 109.2 deg. Focal surface Curvature Radius Thickness Material Index Abbe # length 0 object infinity 0.000 1 flat panel infinity 1.500 glass 1.52 64.2 2 infinity 1.308 3 Lens 1 −0.593 (ASP) 0.384 plastic 1.54 56 −1.10 4 −100.001 (ASP) 0.370 5 stop infinity 0.008 6 Lens 2 0.923 (ASP) 0.427 plastic 1.54 56 0.74 7 −0.593 (ASP) 0.030 8 Lens 3 1.341 (ASP) 0.247 plastic 1.64 22.5 1.21 9 −1.703 (ASP) 0.379 10  IR-filter infinity 0.210 glass 1.52 54.5 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 4 Aspheric Coefficients surface 3 4 6 7 8 9 K: −6.4918E+00 −3.9992E+02 −4.9131E+01 8.9612E−01 −1.5246E+01 −8.1551E+01 A: 2.1426E+00 7.9165E+00 4.7911E+00 −1.2361E−01 1.0724E+00 2.2809E+00 B: −6.7444E+00 2.1246E+00 −6.7622E+01 −3.9616E+01 −4.7639E+01 −2.8547E+01 C: 1.4949E+01 2.5606E+02 −4.2869E+02 2.2480E+02 1.2582E+02 1.5003E+01 D: −1.8735E+01 −2.7263E+03 9.9086E+03 6.1759E+02 9.3780E+02 4.1861E+02 E: 8.6996E+00 −1.4381E+04 8.2215E+04 1.0358E+02 −4.5273E+02 4.3494E+03 F  5.0113E+00 2.3365E+05 −1.9549E+06 −6.2854E+04 −7.4033E+04 −4.8444E+04 G  −5.0411E+00 −1.9075E+05 6.7066E+06 1.9852E+05 2.9307E+05 1.1268E+05

In the second embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the second embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 3 and Table 4 as the following values and satisfy the following conditions:

Embodiment 2 f[mm] 0.38 f1/R2 0.01 Fno 1.40 f2/R3 0.80 FOV[deg.] 109.20 f2/R4 −1.24 |f/(f1 * f2 * f3)| 0.39 f3/R5 0.90 [mm⁻²] f/f1 −0.35 f3/R6 −0.71 f/f2 0.51 R1/R2 0.01 f/f3 0.31 R3/R4 −1.55 f/f23 0.74 R5/R6 −0.79 f1/f23 −2.13 OTL/f 12.84 f1/R1 1.85 (f1 + f2 + f3)/(f1 * f2 * f3) −0.87 [mm⁻²]

Referring to FIGS. 3A, 3B and FIG. 3C, FIG. 3A shows a three-piece compact optical lens system in accordance with a third embodiment of the present invention, FIG. 3B is a partial enlarged view of FIG. 3A, and FIG. 3C shows, in order from left to right, the image plane curve and the distortion curve of the third embodiment of the present invention. A three-piece compact optical lens system in accordance with the third embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 360, a first lens element 310, a stop 300, a second lens element 320, a third lens element 330, an IR cut filter 370, and an image plane 380, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 300 is disposed between the first lens element 310 and the second lens element 320.

The flat panel 360 made of glass is located between an object O and the first lens element 310 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 310 with a negative refractive power has an object-side surface 311 being concave near an optical axis 390 and an image-side surface 312 being concave near the optical axis 390, the object-side surface 311 and the image-side surface 312 are aspheric, and the first lens element 310 is made of plastic material.

The second lens element 320 with a positive refractive power has an object-side surface 321 being convex near the optical axis 390 and an image-side surface 322 being convex near the optical axis 390, the object-side surface 321 and the image-side surface 322 are aspheric, and the second lens element 320 is made of plastic material.

The third lens element 330 with a positive refractive power has an object-side surface 331 being convex near the optical axis 390 and an image-side surface 332 being convex near the optical axis 390, the object-side surface 331 and the image-side surface 332 are aspheric, and the third lens element 330 is made of plastic material.

The IR cut filter 370 made of glass is located between the third lens element 330 and the image plane 380 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the third embodiment is shown in table 5, and the aspheric surface data is shown in table 6.

TABLE 5 Embodiment 3 f(focal length) = 0.36 mm, Fno = 1.30, FOV = 114.6 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.186 3 Lens 1 −0.556 (ASP) 0.367 plastic 1.54 56 −0.81 4 2.575 (ASP) 0.401 5 stop infinity 0.001 6 Lens 2 0.795 (ASP) 0.502 plastic 1.54 56 0.73 7 −0.615 (ASP) 0.031 8 Lens 3 1.048 (ASP) 0.243 plastuc 1.54 56 1.29 9 −1.945 (ASP) 0.409 10  IR- infinity 0.210 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 6 Aspheric Coefficients surface 3 4 6 7 8 9 K: −8.0024E+00 −1.9774E+01 −4.7139E+01 9.2121E−01 −1.1890E+01 −4.5548E+01 A: 2.1115E+00 1.0690E+01 5.7393E+00 4.5153E−01 1.2507E+00 2.5234E+00 B: −6.7769E+00 −1.0853E+01 −6.5651E+01 −4.0583E+01 −4.7072E+01 −2.8089E+01 C: 1.4913E+01 2.0963E+02 −4.8839E+02 2.1330E+02 1.2716E+02 1.5595E+01 D: −1.8780E+01 −2.4878E+03 9.0215E+03 5.8070E+02 9.3021E+02 4.2480E+02 E: 8.6506E+00 −1.0689E+04 7.6354E+04 8.6568E+01 −5.9265E+02 4.3670E+03 F  5.0120E+00 2.4047E+05 −1.9212E+06 −6.1195E+04 −7.5340E+04 −4.8618E+04 G  −4.9036E+00 −5.1120E+05 8.5642E+06 2.1358E+05 2.8301E+05 1.1002E+05

In the third embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the third embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 5 and Table 6 as the following values and satisfy the following conditions:

Embodiment 3 f[mm] 0.36 f1/R2 −0.31 Fno 1.30 f2/R3 0.92 FOV[deg.] 114.60 f2/R4 −1.18 |f/(f1 * f2 * f3)| 0.48 f3/R5 1.23 [mm⁻²] f/f1 −0.45 f3/R6 −0.66 f/f2 0.50 R1/R2 −0.22 f/f3 0.28 R3/R4 −1.29 f/f23 0.68 R5/R6 −0.54 f1/f23 −1.52 OTL/f 13.35 f1/R1 1.45 (f1 + f2 + f3)/(f1 * f2 * f3) −1.60 [mm⁻²]

Referring to FIGS. 4A, 4B and FIG. 4C, FIG. 4A shows a three-piece compact optical lens system in accordance with a fourth embodiment of the present invention, FIG. 4B is a partial enlarged view of FIG. 4A, and FIG. 4C shows, in order from left to right, the image plane curve and the distortion curve of the fourth embodiment of the present invention. A three-piece compact optical lens system in accordance with the fourth embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 460, a first lens element 410, a stop 400, a second lens element 420, a third lens element 430, an IR cut filter 470, and an image plane 480, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 400 is disposed between the first lens element 410 and the second lens element 420.

The flat panel 460 made of glass is located between an object O and the first lens element 410 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 410 with a negative refractive power has an object-side surface 411 being concave near an optical axis 490 and an image-side surface 412 being concave near the optical axis 490, the object-side surface 411 and the image-side surface 412 are aspheric, and the first lens element 410 is made of plastic material.

The second lens element 420 with a positive refractive power has an object-side surface 421 being convex near the optical axis 490 and an image-side surface 422 being convex near the optical axis 490, the object-side surface 421 and the image-side surface 422 are aspheric, and the second lens element 420 is made of plastic material.

The third lens element 430 with a positive refractive power has an object-side surface 431 being convex near the optical axis 490 and an image-side surface 432 being convex near the optical axis 490, the object-side surface 431 and the image-side surface 432 are aspheric, and the third lens element 430 is made of plastic material.

The IR cut filter 470 made of glass is located between the third lens element 430 and the image plane 480 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the fourth embodiment is shown in table 7, and the aspheric surface data is shown in table 8.

TABLE 7 Embodiment 4 f(focal length) = 0.34 mm, Fno = 1.20, FOV = 121.8 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.010 3 Lens 1 −0.504 (ASP) 0.385 plastic 1.54 56 −0.72 4 2.208 (ASP) 0.414 5 stop infinity 0.017 6 Lens 2 1.415 (ASP) 0.508 plastic 1.54 56 0.76 7 −0.510 (ASP) 0.030 8 Lens 3 60.243 (ASP) 0.355 plastic 1.54 56 1.23 9 −0.676 (ASP) 0.472 10  IR- infinity 0.210 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 8 Aspheric Coefficients surface 3 4 6 7 8 9 K: −8.9574E+00 −1.8655E+01 −3.0573E+02 −1.2575E+00 1.5715E+02 −1.2220E−01 A: 1.5447E+00 1.4497E+01 2.8808E+00 2.9669E+00 4.5606E+00 2.2079E+00 B: −4.6133E+00 −2.1546E+02 −1.4255E+01 −3.1094E+01 −3.4642E+01 −9.0007E+00 C: 9.5150E+00 3.1999E+03 −5.6413E+02 5.3776E+01 4.2944E+01 1.2699E+02 D: −1.2115E+02 −1.5598E+04 6.5379E+03 −1.7586E+02 4.0062E+02 −1.0281E+03 E: 8.6388E+00 −1.3702E+05 5.4097E+04 4.6999E+03 1.8345E+03 4.3686E+03 F  −2.6923E+00 1.8193E+06 −1.5332E+06 −3.1483E+04 −3.1188E+04 −1.0830E+04 G  7.1730E−02 −5.3407E+06 7.6274E+06 5.9102E+04 7.4691E+04 1.2056E+04

In the fourth embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the fourth embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 7 and Table 8 as the following values and satisfy the following conditions:

Embodiment 4 f[mm] 0.34 f1/R2 −0.33 Fno 1.20 f2/R3 0.54 FOV[deg.] 121.80 f2/R4 −1.49 |f/(f1 * f2 * f3)| 0.51 f3/R5 0.02 [mm⁻²] f/f1 −0.48 f3/R6 −1.82 f/f2 0.45 R1/R2 −0.23 f/f3 0.28 R3/R4 −2.78 f/f23 0.60 R5/R6 −89.08 f1/f23 −1.26 OTL/f 14.38 f1/R1 1.42 (f1 + f2 + f3)/(f1 * f2 * f3) −1.90 [mm⁻²]

Referring to FIGS. 5A, 5B and FIG. 5C, FIG. 5A shows a three-piece compact optical lens system in accordance with a fifth embodiment of the present invention, FIG. 5B is a partial enlarged view of FIG. 5A, and FIG. 5C shows, in order from left to right, the image plane curve and the distortion curve of the fifth embodiment of the present invention. A three-piece compact optical lens system in accordance with the fifth embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 560, a first lens element 510, a stop 500, a second lens element 520, a third lens element 530, an IR cut filter 570, and an image plane 580, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 500 is disposed between the first lens element 510 and the second lens element 520.

The flat panel 560 made of glass is located between an object O and the first lens element 510 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 510 with a negative refractive power has an object-side surface 511 being concave near an optical axis 590 and an image-side surface 512 being convex near the optical axis 590, the object-side surface 511 and the image-side surface 512 are aspheric, and the first lens element 510 is made of plastic material.

The second lens element 520 with a positive refractive power has an object-side surface 521 being convex near the optical axis 590 and an image-side surface 522 being convex near the optical axis 590, the object-side surface 521 and the image-side surface 522 are aspheric, and the second lens element 520 is made of plastic material.

The third lens element 530 with a positive refractive power has an object-side surface 531 being convex near the optical axis 590 and an image-side surface 532 being convex near the optical axis 590, the object-side surface 531 and the image-side surface 532 are aspheric, and the third lens element 530 is made of plastic material.

The IR cut filter 570 made of glass is located between the third lens element 530 and the image plane 580 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the fifth embodiment is shown in table 9, and the aspheric surface data is shown in table 10.

TABLE 9 Embodiment 5 f(focal length) = 0.39 mm, Fno = 1.40, FOV = 108.3 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.565 3 Lens 1 −0.664 (ASP) 0.409 plastic 1.54 56 −1.38 4 −6.569 (ASP) 0.391 5 stop infinity 0.016 6 Lens 2 0.835 (ASP) 0.364 plastic 1.54 56 0.71 7 −0.621 (ASP) 0.034 8 Lens 3 2.073 (ASP) 0.240 plastic 1.64 22.5 1.25 9 −1.274 (ASP) 0.392 10  IR- infinity 0.210 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 10 Aspheric Coefficients surface 3 4 6 7 8 9 K: −5.7238E+00 −4.0067E+02 −5.2904E+01 8.2614E−01 −1.0481E+02 −4.2865E+01 A: 2.0697E+00 5.3198E+00 5.3103E+00 3.6295E−02 8.3613E−01 1.8141E+00 B: −6.5342E+00 4.9908E+00 −6.2975E+01 −3.9570E+01 −4.8414E+01 −2.8553E+01 C: 1.4819E+01 2.3533E+02 −4.3756E+02 2.3037E+02 1.4503E+02 1.8849E+01 D: −1.8750E+01 −2.6669E+03 9.9371E+03 7.9640E+02 1.1648E+03 5.0107E+02 E: 8.6757E+00 −1.0270E+04 8.0681E+04 8.9252E+02 −2.4243E+02 4.0494E+03 F  5.0286E+00 2.4881E+05 −1.9089E+06 −5.9985E+04 −7.7409E+04 −4.8657E+04 G  −4.9380E+00 −5.7851E+05 7.8503E+06 1.7726E+05 2.7741E+05 1.1330E+05

In the fifth embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the fifth embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 9 and Table 10 as the following values and satisfy the following conditions:

Embodiment 5 f[mm] 0.39 f1/R2 0.21 Fno 1.40 f2/R3 0.85 FOV[deg.] 108.30 f2/R4 −1.15 |f/(f1 * f2 * f3)| 0.32 f3/R5 0.60 [mm⁻²] f/f1 −0.28 f3/R6 −0.98 f/f2 0.55 R1/R2 0.10 f/f3 0.31 R3/R4 −1.34 f/f23 0.76 R5/R6 −1.63 f1/f23 −2.68 OTL/f 13.08 f1/R1 2.08 (f1 + f2 + f3)/(f1 * f2 * f3) −0.47 [mm⁻²]

Referring to FIGS. 6A, 6B and FIG. 6C, FIG. 6A shows a three-piece compact optical lens system in accordance with a sixth embodiment of the present invention, FIG. 6B is a partial enlarged view of FIG. 6A, and FIG. 6C shows, in order from left to right, the image plane curve and the distortion curve of the sixth embodiment of the present invention. A three-piece compact optical lens system in accordance with the sixth embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 660, a first lens element 610, a stop 600, a second lens element 620, a third lens element 630, an IR cut filter 670, and an image plane 680, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 600 is disposed between the first lens element 610 and the second lens element 620.

The flat panel 660 made of glass is located between an object O and the first lens element 610 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 610 with a negative refractive power has an object-side surface 611 being concave near an optical axis 690 and an image-side surface 612 being concave near the optical axis 690, the object-side surface 611 and the image-side surface 612 are aspheric, and the first lens element 610 is made of plastic material.

The second lens element 620 with a positive refractive power has an object-side surface 621 being convex near the optical axis 690 and an image-side surface 622 being convex near the optical axis 690, the object-side surface 621 and the image-side surface 622 are aspheric, and the second lens element 620 is made of plastic material.

The third lens element 630 with a positive refractive power has an object-side surface 631 being concave near the optical axis 690 and an image-side surface 632 being convex near the optical axis 690, the object-side surface 631 and the image-side surface 632 are aspheric, and the third lens element 630 is made of plastic material.

The IR cut filter 670 made of glass is located between the third lens element 630 and the image plane 680 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the sixth embodiment is shown in table 11, and the aspheric surface data is shown in table 12.

TABLE 11 Embodiment 6 f(focal length) = 0.41 mm, Fno = 1.50, FOV = 108.4 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.335 3 Lens 1 −0.853 (ASP) 0.376 plastic 1.54 56 −1.02 4 1.820 (ASP) 0.377 5 stop infinity 0.012 6 Lens 2 0.971 (ASP) 0.294 plastic 1.64 22.5 0.71 7 −0.756 (ASP) 0.030 8 Lens 3 −3.590 (ASP) 0.247 plastic 1.64 22.5 1.12 9 −0.614 (ASP) 0.446 10  IR- infinity 0.210 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 12 Aspheric Coefficients surface 3 4 6 7 8 9 K: −2.2346E+00 −4.8511E+02 −1.1408E+02 2.4188E−01 −1.9012E+01 −2.1609E+00 A: 2.9713E+00 5.3750E+00 7.4884E+00 1.5791E+00 2.3434E+00 2.3264E+00 B: −1.1069E+01 5.7163E+00 −1.0708E+02 −7.1289E+01 −5.7222E+01 −2.7097E+01 C: 3.1272E+01 5.5173E+02 −9.3982E+02 5.5065E+02 3.4089E+02 1.1892E+02 D: −5.0186E+01 −6.4911E+03 2.5277E+04 2.3419E+03 2.9363E+03 1.2778E+03 E: 2.8950E+01 −3.6649E+04 2.6515E+05 −3.3832E+03 2.4960E+03 1.0108E+04 F  2.0721E+01 9.3083E+05 −7.3370E+06 −3.0990E+05 −3.4077E+05 −2.1811E+05 G  −2.5192E+01 −3.5967E+06 3.4937E+07 9.6920E+05 1.1034E+06 6.7718E+05

In the sixth embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the sixth embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 11 and Table 12 as the following values and satisfy the following conditions:

Embodiment 6 f[mm] 0.41 f1/R2 −0.56 Fno 1.50 f2/R3 0.73 FOV[deg.] 108.40 f2/R4 −0.94 |f/(f1 * f2 * f3)| 0.51 f3/R5 −0.31 [mm⁻²] f/f1 −0.40 f3/R6 −1.82 f/f2 0.57 R1/R2 −0.47 f/f3 0.36 R3/R4 −1.28 f/f23 0.79 R5/R6 5.85 f1/f23 −1.97 OTL/f 11.88 f1/R1 1.19 (f1 + f2 + f3)/(f1 * f2 * f3) −1.01 [mm⁻²]

Referring to FIGS. 7A, 7B and FIG. 7C, FIG. 7A shows a three-piece compact optical lens system in accordance with a seventh embodiment of the present invention, FIG. 7B is a partial enlarged view of FIG. 7A, and FIG. 7C shows, in order from left to right, the image plane curve and the distortion curve of the seventh embodiment of the present invention. A three-piece compact optical lens system in accordance with the seventh embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 760, a first lens element 710, a stop 700, a second lens element 720, a third lens element 730, an IR cut filter 770, and an image plane 780, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 700 is disposed between the first lens element 710 and the second lens element 720.

The flat panel 760 made of glass is located between an object O and the first lens element 710 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 710 with a negative refractive power has an object-side surface 711 being concave near an optical axis 790 and an image-side surface 712 being concave near the optical axis 790, the object-side surface 711 and the image-side surface 712 are aspheric, and the first lens element 710 is made of plastic material.

The second lens element 720 with a positive refractive power has an object-side surface 721 being convex near the optical axis 790 and an image-side surface 722 being convex near the optical axis 790, the object-side surface 721 and the image-side surface 722 are aspheric, and the second lens element 720 is made of plastic material.

The third lens element 730 with a positive refractive power has an object-side surface 731 being convex near the optical axis 790 and an image-side surface 732 being convex near the optical axis 790, the object-side surface 731 and the image-side surface 732 are aspheric, and the third lens element 730 is made of plastic material.

The IR cut filter 770 made of glass is located between the third lens element 730 and the image plane 780 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the seventh embodiment is shown in table 13, and the aspheric surface data is shown in table 14.

TABLE 13 Embodiment 7 f(focal length) = 0.36 mm, Fno = 1.20, FOV = 129.4 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 object infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.028 3 Lens 1 −0.489 (ASP) 0.265 plastic 1.54 56 −0.71 4 2.118 (ASP) 0.498 5 stop infinity −0.014 6 Lens 2 0.887 (ASP) 0.414 plastic 1.54 56 1.11 7 −1.573 (ASP) 0.034 8 Lens 3 1.496 (ASP) 0.367 plastic 1.54 56 0.78 9 −0.544 (ASP) 0.504 10  IR- infinity 0.210 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 14 Aspheric Coefficients surface 3 4 6 7 8 9 K: −1.0288E+01 2.9716E+00 −3.9551E+01 8.7948E+00 −1.1155E+02 2.5315E−02 A: 2.2526E+00 1.0575E+01 2.4959E+00 1.4729E−01 2.7440E+00 6.0590E−01 B: −7.2346E+00 −8.1161E+01 1.2231E+01 −5.7392E+00 −3.3256E+01 2.4679E+01 C: 1.4705E+01 1.1763E+03 −7.4918E+02 4.7381E+00 1.0577E+02 −1.1530E+02 D: −1.6762E+01 −7.4568E+03 3.8984E+03 −6.0267E+02 3.2770E+02 −2.8869E+02 E: 8.4455E+00 −2.1681E+04 9.6229E+04 4.3158E+03 1.4087E+03 6.3091E+03 F  7.5050E−01 4.7807E+05 −1.4250E+06 −1.5818E+04 −5.3255E+04 −2.8925E+04 G  −1.7802E+00 −1.4468E+06 5.4193E+06 2.5578E+04 1.6613E+05 4.5475E+04

In the seventh embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the seventh embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 13 and Table 14 as the following values and satisfy the following conditions:

Embodiment 7 f[mm] 0.36 f1/R2 −0.33 Fno 1.20 f2/R3 1.25 FOV[deg.] 129.40 f2/R4 −0.70 |f/(f1 * f2 * f3)| 0.59 f3/R5 0.52 [mm⁻²] f/f1 −0.51 f3/R6 −1.44 f/f2 0.32 R1/R2 −0.23 f/f3 0.46 R3/R4 −0.56 f/f23 0.62 R5/R6 −2.75 f1/f23 −1.21 OTL/f 13.39 f1/R1 1.44 (f1 + f2 + f3)/(f1 * f2 * f3) −1.94 [mm⁻²]

Referring to FIGS. 8A, 8B and FIG. 8C, FIG. 8A shows a three-piece compact optical lens system in accordance with a eighth embodiment of the present invention, FIG. 8B is a partial enlarged view of FIG. 8A, and FIG. 8C shows, in order from left to right, the image plane curve and the distortion curve of the eighth embodiment of the present invention. A three-piece compact optical lens system in accordance with the eighth embodiment of the present invention comprises, in order from an object side to an image side: a flat panel 860, a first lens element 810, a stop 800, a second lens element 820, a third lens element 830, an IR cut filter 870, and an image plane 880, wherein the three-piece compact optical lens system has a total of three lens elements with refractive power. The stop 800 is disposed between the first lens element 810 and the second lens element 820.

The flat panel 860 made of glass is located between an object O and the first lens element 810 and has no influence on the focal length of the three-piece compact optical lens system.

The first lens element 810 with a negative refractive power has an object-side surface 811 being concave near an optical axis 890 and an image-side surface 812 being concave near the optical axis 890, the object-side surface 811 and the image-side surface 812 are aspheric, and the first lens element 810 is made of plastic material.

The second lens element 820 with a positive refractive power has an object-side surface 821 being convex near the optical axis 890 and an image-side surface 822 being convex near the optical axis 890, the object-side surface 821 and the image-side surface 822 are aspheric, and the second lens element 820 is made of plastic material.

The third lens element 830 with a positive refractive power has an object-side surface 831 being convex near the optical axis 890 and an image-side surface 832 being convex near the optical axis 890, the object-side surface 831 and the image-side surface 832 are aspheric, and the third lens element 830 is made of plastic material.

The IR cut filter 870 made of glass is located between the third lens element 830 and the image plane 880 and has no influence on the focal length of the three-piece compact optical lens system.

The detailed optical data of the eighth embodiment is shown in table 15, and the aspheric surface data is shown in table 16.

TABLE 15 Embodiment 8 f(focal length) = 0.39 mm, Fno = 1.60, FOV = 111.0 deg. sur- Curvature Thick- Mat- In- Abbe Focal face Radius ness erial dex # length 0 pbject infinity 0.000 1 flat infinity 1.500 glass 1.52 64.2 panel 2 infinity 1.192 3 Lens 1 −0.862 (ASP) 0.267 plastic 1.64 22.5 −0.92 4 2.251 (ASP) 0.413 5 stop infinity 0.023 6 Lens 2 1.124 (ASP) 0.391 plastic 1.54 56 1.06 7 −1.060 (ASP) 0.115 8 Lens 3 0.353 (ASP) 0.264 plastic 1.54 56 0.81 9 1.280 (ASP) 0.337 10  IR- infinity 0.145 glass 1.52 54.5 filter 11  infinity infinity 12  Image infinity 0.000 plane

TABLE 16 Aspheric Coefficients surface 3 4 6 7 8 9 K: −1.0334E+01 −3.2949E+02 −6.5202E+01 2.7538E+00 −3.9237E−01 4.8950E+00 A: 2.3249E+00 6.4379E+00 −3.1459E−01 −1.0773E+01 −9.2564E+00 3.8193E+00 B: −5.4793E+00 −2.9503E+00 7.7474E+00 6.4661E+01 8.2212E+01 −4.3656E+01 C: 8.8566E+00 4.9837E+01 −4.4062E+02 −1.0320E+02 −1.0312E+03 9.7123E+01 D: −5.9101E+00 4.4457E+02 9.0463E+03 −1.4259E+03 5.8260E+03 −7.6089E+01 E: 2.3959E−03 −1.7922E+03 −2.8651E+05 4.1769E+03 −1.5877E+04 1.0505E+02 F  7.0452E−01 −2.6077E+03 3.0193E+06 −1.9325E+03 8.8566E+03 −6.6612E+02 G  9.6205E−03 −5.9073E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

In the eighth embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the first embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the first embodiment with corresponding values for the eighth embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 15 and Table 16 as the following values and satisfy the following conditions:

Embodiment 8 f[mm] 0.39 f1/R2 −0.41 Fno 1.60 f2/R3 0.95 FOV[deg.] 111.00 f2/R4 −1.00 |f/(f1 * f2 * f3)| 0.49 f3/R5 2.29 [mm⁻²] f/f1 −0.42 f3/R6 0.63 f/f2 0.36 R1/R2 −0.38 f/f3 0.48 R3/R4 −1.06 f/f23 0.76 R5/R6 0.28 f1/f23 −1.81 OTL/f 12.02 f1/R1 1.07 (f1 + f2 + f3)/(f1 * f2 * f3) −1.20 [mm⁻²]

In the present three-piece compact optical lens system, the lens elements can be made of plastic or glass. If the lens elements are made of plastic, the cost will be effectively reduced. If the lens elements are made of glass, there is more freedom in distributing the refractive power of the three-piece compact optical lens system. Plastic lens elements can have aspheric surfaces, which allow more design parameter freedom (than spherical surfaces), so as to reduce the aberration and the number of the lens elements, as well as the total track length of the three-piece compact optical lens system.

In the present three-piece compact optical lens system, if the object-side or the image-side surface of the lens elements with refractive power is convex and the location of the convex surface is not defined, the object-side or the image-side surface of the lens elements near the optical axis is convex. If the object-side or the image-side surface of the lens elements is concave and the location of the concave surface is not defined, the object-side or the image-side surface of the lens elements near the optical axis is concave.

While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

What is claimed is:
 1. A three-piece compact optical lens system, in order from an object side to an image side, comprising: a flat panel made of glass; a first lens element with a negative refractive power, having an object-side surface being concave near an optical axis, at least one of the object-side surface and an image-side surface of the first lens element being aspheric; a stop; a second lens element with a positive refractive power, having an object-side surface being convex near an optical axis and an image-side surface being convex near the optical axis, at least one of the object-side surface and the image-side surface of the second lens element being aspheric; and a third lens element with a positive refractive power, at least one of an object-side surface and an image-side surface of the third lens element being aspheric; wherein the three-piece compact optical lens system has a total of three lens elements with refractive power, the three-piece compact optical lens system has a maximum view angle FOV, a distance from an object on an object-side surface of the flat panel to an image plane along the optical axis is OTL, a focal length of the three-piece compact optical lens system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a radius of curvature of the object-side surface of the first lens element is R1, and they satisfy the relations: 90 degrees<FOV<140 degrees; 2 mm<OTL<6 mm; 0.2 mm⁻²<|f/(f1*f2*f3)|<0.7 mm⁻²; 0.6<f1/R1<2.4.
 2. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the three-piece compact optical lens system is f, the focal length of the first lens element is f1, and they satisfy the relation: −0.7<f/f1<−0.1.
 3. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the three-piece compact optical lens system is f, the focal length of the second lens element is f2, and they satisfy the relation: 0.1<f/f2<0.75.
 4. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the three-piece compact optical lens system is f, the focal length of the third lens element is 13, and they satisfy the relation: 0.07<f/f3<0.68.
 5. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the three-piece compact optical lens system is f, a focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: 0.4<f/f23<1.0.
 6. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the first lens element is f1, a focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: −2.9<f1/f23<−1.0.
 7. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the first lens element is f1, a radius of curvature of the image-side surface of the first lens element is R2, and they satisfy the relation: −1.0<f1/R2<0.6.
 8. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the second lens element is f2, a radius of curvature of the object-side surface of the second lens element is R3, and they satisfy the relation: 0.2<f2/R3<1.6.
 9. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the second lens element is f2, a radius of curvature of the image-side surface of the second lens element is R4, and they satisfy the relation: −1.8<f2/R4<−0.4.
 10. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the third lens element is f3, a radius of curvature of the object-side surface of the third lens element is R5, and they satisfy the relation: −0.7<f3/R5<2.7.
 11. The three-piece compact optical lens system as claimed in claim 1, wherein the focal length of the third lens element is f3, a radius of curvature of the image-side surface of the third lens element is R6, and they satisfy the relation: −2.1<f3/R6<1.0.
 12. The three-piece compact optical lens system as claimed in claim 1, the radius of curvature of the object-side surface of the first lens element is R1, a radius of curvature of the image-side surface of the first lens element is R2, and they satisfy the relation: −0.9<R1/R2<0.6.
 13. The three-piece compact optical lens system as claimed in claim 1, a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, and they satisfy the relation: −3.2<R3/R4<−0.1.
 14. The three-piece compact optical lens system as claimed in claim 1, a radius of curvature of the object-side surface of the third lens element is R5, a radius of curvature of the image-side surface of the third lens element is R6, and they satisfy the relation: −95<R5/R6<10.
 15. The three-piece compact optical lens system as claimed in claim 1, the focal length of the three-piece compact optical lens system is f, the distance from the object on the object-side surface of the flat panel to the image plane along the optical axis is OTL, and they satisfy the relation: 8.0<OTL/f<18.0.
 16. The three-piece compact optical lens system as claimed in claim 1, the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the third lens element is f3, and they satisfy the relation: −2.4 mm⁻²<(f1+f2+f3)/(f1*f2*f3)<−0.1 mm⁻². 